The invention relates to a roller, in particular a castor-type roller, with the rotational movement of the running wheel and optionally the pivoting movement of the running wheel being fixable, with an operating shaft which passes through a control cam of the roller and on which an electric motor acts via a gear mechanism to operate it.
A roller which can be switched by means of a rocker pedal with a view to being able to fix the rotational movement of the running wheel and the pivoting movement is disclosed by U.S. Pat. No. 5,377,372. The pedal extends in the center of the chassis of a movable bed. This produces a quite complicated transmission mechanism with respect to the rollers.
It is already known from DE-A1 43 18 546 to use an electric motor to control an operating shaft passing through a control cam of the roller. The electric motor and gear mechanism are aligned in such a way as to extend a push rod, which turns the operating shaft via an articulated pivot lever and consequently turns the control cam, by which the described functions are performed. Here, too, a not inconsiderable complexity is involved.